import type { Breadcrumb, PageDocument } from '#web-runtime/types';
import { toPublicHref } from '#i18n/content-href';

export type JsonLd = Record<string, unknown>;

/**
 * schema.org `BreadcrumbList` for a resolved breadcrumb trail. Positions are
 * 1-based. The current page (the last crumb) intentionally omits `item` — per
 * Google's guidance it is where the user already is, so it carries no URL.
 */
export function breadcrumbListJsonLd(items: Breadcrumb[]): JsonLd {
  return {
    '@context': 'https://schema.org',
    '@type': 'BreadcrumbList',
    'itemListElement': items.map((item, index) => ({
      '@type': 'ListItem',
      'position': index + 1,
      'name': item.label,
      ...(index < items.length - 1 ? { item: toPublicHref(item.href) } : {})
    }))
  };
}

/**
 * schema.org `Article` for an editorial page. Only the fields the backend actually knows are
 * emitted — a date or image invented here would be markup that contradicts the page.
 *
 * `dateModified` is omitted when it equals `datePublished`, since repeating it tells a crawler
 * nothing, and the whole object is skipped by the caller when there is no publication date:
 * an `Article` without one is markup Google will ignore anyway.
 */
export function articleJsonLd(page: PageDocument): JsonLd | null {
  if (!page.publishedAt) {
    return null;
  }

  const image = page.hero?.media?.url;

  return {
    '@context': 'https://schema.org',
    '@type': 'Article',
    'headline': page.seo.title || page.title,
    ...(page.seo.description ? { description: page.seo.description } : {}),
    'datePublished': page.publishedAt,
    ...(page.updatedAt && page.updatedAt !== page.publishedAt
      ? { dateModified: page.updatedAt }
      : {}),
    ...(image ? { image: [image] } : {}),
    'inLanguage': page.locale
  };
}

export function JsonLdScript({ data }: { data: JsonLd }) {
  return (
    <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(data) }} />
  );
}